1. Technical Field
This invention relates to a scalable hosting platform and more particularly, to a multi-layer system for a scalable hosting platform.
2. Related Art
In a hosting environment, a single hosting server may provide services to a number of hosts. This may reduce hosting cost. However, a shared single server may be overloaded depending on a number of requests for hosts, types of requests, etc. The overloaded single server may lack scalability.
To overcome lack of scalability, a load balancer may be disposed in front of a cluster of hosting servers and distributes requests to the hosting servers. The load balancer is a popular tool to support scalability of hosting servers. Hosts usually share one Internet Protocol (IP) address. To differentiate hosts having the one IP address, an application level load balancer may be needed. The application level load balancer may recognize each host despite the one IP address and provide separate scalable service to each host.
It is well appreciated in the art that a network framework may be defined with multiple layers including an application layer, a transport layer (e.g., Transmission Control Protocol (“TCP”) layer), a network layer (e.g. IP layer), and a physical layer. The application layer corresponds to the Open System Interconnection (“OSI”) layer 7, and the transport layer corresponds to the OSI layer 4. Recognizing specific information at higher layers may require higher overhead, which may lead to a lower throughput. For instance, a layer 7 (L7) load balancer may have a lower throughput than a layer 4 (L4) load balancer. As a result, the L7 load balancer, although it is able to distinguish multiple hosts sharing the one IP address, may reduce overall scalability.
The load balancer also may be a single point of failure. Specifically, if the load balancer fails, all of hosting servers will fail accordingly. This may result in unavailability of hosting services. High Availability (HA) solutions may relieve this failure of the load balancer. One example of HA solutions includes primary and secondary load balancers. The secondary load balancer may replace the primary load balancer in case of failure of the primary load balancer. HA solutions may not be, however, free from failure. The failure of HA solutions may result in unavailability of hosting services.